Sparking device.



No. 702,695. Patented lune l7, I902.

'D. M. BLISS.

SPABKING DEVICE.

(Application filed. Nov. 7, 1901.

' (mi Model.)

,ZZovmfd Z1615 T Ncnms FEYERS 0o, PHD'O'LITHLL,WASHINGTON-A1C UNITED STATES PATENT OFFICE.

DONALD M. BLISS, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR TO I'IOLTZER- CABOT ELECTRIC COMPANY, OF BROOKLINE, MASSACHUSETTS, A COR- PORATION OF MASSACHUSETTS.

SPARKENG DEVICE.

SPECIFICATION forming part of Letters Patent No. 702,695, dated June 17, 1902.

. Serial No, 81,432. (No model.)

To all whom. it may concern:

Be it known that I, DONALD M. BLIss, of Brookline, county of Norfolk, and State of Massachusetts, have invented an Improve- 5 ment in Sparking Devices, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

The present invention relates to a sparking device for explosion-engines, &c., and is especially adapted for use with such engines when used for locomotive power, as for propelling boatsor vehicles.

The object of the invention is to utilize as the generator of the current a dynamo driven by the vehicle which is being propelled, it being essential, therefore, that the dynamo should be capable of operating through wide variations in speed and giving sufficient current to produce a spark under all conditions.

'It is impracticable to use a shunt-wound dynamo for this purpose, for the reason that if the speed is increased to any considerable extent beyond that for which the fields are wound the winding will become overheated or destroyed, while if the speed is reduced to any material extent below that for which the fields are wound the field-coil will not be excited and current will not be produced. On

the other hand, where a series-wound dynamo is used while the field can be wound so as to cause the production of current in spite of wide variations in speed it is obvious that each time the sparking contacts are separated to produce the spark the field-circuit will be opened, and the field will lose its strength to such an extent that it will not build up during the time when the spark-gap is closed. To overcome these difficulties and also to obviate the need of employing mechanical speedregulating devices, which have sometimes been used to regulate the speed of a dynamo, the system is arranged in accordance with the invention, so that an artificial load is introduced into the circuit when the spark-gap is opened, the introduction of said load being controlled in response to the opening and closing of the spark-gap.

Figure 1 is a diagram of a system embody- 5o ing the invention and showing the spark-gap open. Fig. 2 is a similar diagram showing the spark-gap closed and also showing a slight modification, and Fig. 3 a diagram showing a further modification.

Referring to Fig. 1, the contacts a and a of the spark-gap are arranged in a circuit which is in series with the field-coils b and the armature-coils c of a series-wound dynamo which generates the current to produce the spark when the contacts a. and a are separated. In an explosion engine, however, the gap is opened and closed very rapidly, and it is obvious that each time it is opened the current will be discharged from the fieldcoils Z), which will not build up sufiiciently to remain excited during the time that the spark-gap is closed. In order, therefore, to maintain the field strength, the system is provided with a supplemental circuit containing a load, such as a storage battery (I, Fig. 1, or resistance d Fig. 2, and the circuit containing the said load is arranged to be placed in series with the field-coils b in response to the separation of the spark-gap terminals. To accomplish this, the supplemental circuit, containing the load, is provided with a break having a circuit-closer which is adapted to operate in response to the flow of current through the circuit containing the spark-gap. It is obvious that various means may be employed to operate the said circuit-closer and that either electrical or mechanical devices may be employed for the purpose, as shown. One terminal of the 8 supplemental circuit is carried by an armature d which is under the control of an electromagnet b in the main circuit, so that when the contacts a and o are together, as shown in Fig. 2, closing the main circuit, the elec- 9o tromagnet b will be energized, attracting the armature d and carrying the same away from the contact 61 thereby breaking the auxiliary circuit, so that the entire current flows through the main circuit ready to discharge 5 when the spark-gap is opened. Upon the opening of the spark-gap,however,the electromagnet 1) becomes deonergized, so that the armature (1 moves into contact With the contactpiece d closing the auxiliary circuit through a resistance or otherload which then is in series with the field-coils b, so that the said field-coils remain excited. The load (Z may be of any suitable nature, being indicated in Fig. 1 as a few cells of a storage battery and in Fig. 2 as a resistance (Z having an adjustable contact member (1, whereby the amount of the resistance can be regulated, if desired. The same result,however,can be obtained by mechanical means, as indicated in Fig. 3, in which the resistance (Z is shown as contained in a circuit having a terminal (Z Which is adapted to cooperate with a circuitclosing member a", connected with and carried by the member a and so arranged that in the movement of the said member (0 which separates the same from the member a to break the main circuit and produce a spark, the member a will come into contact with the contact-piece (Z completing the auxiliary circuit through the resistance.

It is not intended to limit the invention to the specific construction shown and described, since modifications may be made without departing from the invention.

I claim 1. The combination withaseries-Wound dynamo; of a sparking device in the main circuit thereof; a branch circuit connecting the conductors of the main circuit; a circuit-controller in said branch circuit; and means for operating said circuit-controller to close said branch circuit when the main circuit is open and vice versa, substantially as and for the purpose described.

2. The combination withaseries-wounddynamo; of a sparking device in the main circuit thereof; a branch circuit connecting the conductors of the main circuit; a circuit-controller in said branch circuit; and means 0perated by said sparking device for operating said circuit-controller, substantially as described.

8. The combination with a series-wound dynamo; of a sparking device in the main circuit thereof; a branch circuit connecting the conductors of the main circuit; an adjustable load in said branch circuit; a circuit-controller in said branch circuit; and means operated by said sparking device for operating said circuit-controller, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

DONALD M. BLISS.

Witnesses:

HENRY .T. Liver-mums, JAS. J. MALoNEY. 

